This is the logger class that I use. The private Log() method has EventLog.WriteEntry() in it, which is how you actually write to the event log. I'm including all of this code here because it's handy. In addition to logging, this class will also make sure the message isn't too long to write to the event log (it will truncate the message). If the message was too long, you'd get an exception. The caller can also specify the source. If the caller doesn't, this class will get the source. Hope it helps.
By the way, you can get an ObjectDumper from the web. I didn't want to post all that here. I got mine from here: C:\Program Files (x86)\Microsoft Visual Studio 10.0\Samples\1033\CSharpSamples.zip\LinqSamples\ObjectDumper
using System;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.Linq;
using System.Reflection;
using Xanico.Core.Utilities;
namespace Xanico.Core
{
/// <summary>
/// Logging operations
/// </summary>
public static class Logger
{
// Note: The actual limit is higher than this, but different Microsoft operating systems actually have
// different limits. So just use 30,000 to be safe.
private const int MaxEventLogEntryLength = 30000;
/// <summary>
/// Gets or sets the source/caller. When logging, this logger class will attempt to get the
/// name of the executing/entry assembly and use that as the source when writing to a log.
/// In some cases, this class can't get the name of the executing assembly. This only seems
/// to happen though when the caller is in a separate domain created by its caller. So,
/// unless you're in that situation, there is no reason to set this. However, if there is
/// any reason that the source isn't being correctly logged, just set it here when your
/// process starts.
/// </summary>
public static string Source { get; set; }
/// <summary>
/// Logs the message, but only if debug logging is true.
/// </summary>
/// <param name="message">The message.</param>
/// <param name="debugLoggingEnabled">if set to <c>true</c> [debug logging enabled].</param>
/// <param name="source">The name of the app/process calling the logging method. If not provided,
/// an attempt will be made to get the name of the calling process.</param>
public static void LogDebug(string message, bool debugLoggingEnabled, string source = "")
{
if (debugLoggingEnabled == false) { return; }
Log(message, EventLogEntryType.Information, source);
}
/// <summary>
/// Logs the information.
/// </summary>
/// <param name="message">The message.</param>
/// <param name="source">The name of the app/process calling the logging method. If not provided,
/// an attempt will be made to get the name of the calling process.</param>
public static void LogInformation(string message, string source = "")
{
Log(message, EventLogEntryType.Information, source);
}
/// <summary>
/// Logs the warning.
/// </summary>
/// <param name="message">The message.</param>
/// <param name="source">The name of the app/process calling the logging method. If not provided,
/// an attempt will be made to get the name of the calling process.</param>
public static void LogWarning(string message, string source = "")
{
Log(message, EventLogEntryType.Warning, source);
}
/// <summary>
/// Logs the exception.
/// </summary>
/// <param name="ex">The ex.</param>
/// <param name="source">The name of the app/process calling the logging method. If not provided,
/// an attempt will be made to get the name of the calling process.</param>
public static void LogException(Exception ex, string source = "")
{
if (ex == null) { throw new ArgumentNullException("ex"); }
if (Environment.UserInteractive)
{
Console.WriteLine(ex.ToString());
}
Log(ex.ToString(), EventLogEntryType.Error, source);
}
/// <summary>
/// Recursively gets the properties and values of an object and dumps that to the log.
/// </summary>
/// <param name="theObject">The object to log</param>
[SuppressMessage("Microsoft.Globalization", "CA1303:Do not pass literals as localized parameters", MessageId = "Xanico.Core.Logger.Log(System.String,System.Diagnostics.EventLogEntryType,System.String)")]
[SuppressMessage("Microsoft.Naming", "CA1720:IdentifiersShouldNotContainTypeNames", MessageId = "object")]
public static void LogObjectDump(object theObject, string objectName, string source = "")
{
const int objectDepth = 5;
string objectDump = ObjectDumper.GetObjectDump(theObject, objectDepth);
string prefix = string.Format(CultureInfo.CurrentCulture,
"{0} object dump:{1}",
objectName,
Environment.NewLine);
Log(prefix + objectDump, EventLogEntryType.Warning, source);
}
private static void Log(string message, EventLogEntryType entryType, string source)
{
// Note: I got an error that the security log was inaccessible. To get around it, I ran the app as administrator
// just once, then I could run it from within VS.
if (string.IsNullOrWhiteSpace(source))
{
source = GetSource();
}
string possiblyTruncatedMessage = EnsureLogMessageLimit(message);
EventLog.WriteEntry(source, possiblyTruncatedMessage, entryType);
// If we're running a console app, also write the message to the console window.
if (Environment.UserInteractive)
{
Console.WriteLine(message);
}
}
private static string GetSource()
{
// If the caller has explicitly set a source value, just use it.
if (!string.IsNullOrWhiteSpace(Source)) { return Source; }
try
{
var assembly = Assembly.GetEntryAssembly();
// GetEntryAssembly() can return null when called in the context of a unit test project.
// That can also happen when called from an app hosted in IIS, or even a windows service.
if (assembly == null)
{
assembly = Assembly.GetExecutingAssembly();
}
if (assembly == null)
{
// From http://stackoverflow.com/a/14165787/279516:
assembly = new StackTrace().GetFrames().Last().GetMethod().Module.Assembly;
}
if (assembly == null) { return "Unknown"; }
return assembly.GetName().Name;
}
catch
{
return "Unknown";
}
}
// Ensures that the log message entry text length does not exceed the event log viewer maximum length of 32766 characters.
private static string EnsureLogMessageLimit(string logMessage)
{
if (logMessage.Length > MaxEventLogEntryLength)
{
string truncateWarningText = string.Format(CultureInfo.CurrentCulture, "... | Log Message Truncated [ Limit: {0} ]", MaxEventLogEntryLength);
// Set the message to the max minus enough room to add the truncate warning.
logMessage = logMessage.Substring(0, MaxEventLogEntryLength - truncateWarningText.Length);
logMessage = string.Format(CultureInfo.CurrentCulture, "{0}{1}", logMessage, truncateWarningText);
}
return logMessage;
}
}
}